There is not a single toothpaste brand that won’t promise you whiter teeth in just 14 days.

No, really.

Even the plain, generic Colgate they sell on those one-euro stores says somewhere in the package that your smile will shine like a bleached doctor’s coat in two weeks time. You can’t read it because it’s in a tiny font and in an obscure eastern european language, but it’s there. All toothpastes guarantee the frostiness of your dentition before the moon takes a complete new form again.

How come, then, after all these years of scrubbing our fangs, tube after tube after tube of menthol flavoured toothpaste — some of them with “whiteness crystals” in them — , our choppers still maintain their yellowish colouration?The logic may be flawed here, but if a product promises something to be accomplished in 14 days and you use it for 28 the result must be at least double. Repeat the process indefinitely and nothing but perfection should result.

And yet only celebrities and perfect lunatics seem able to get their teeth to blind others when they smile. On the streets what you see is the whole spectrum of the yellow hue, except the fairest one. What gives?

First of all our teeth are not supposed to be completely white. To avoid going too scientific here let’s just say the enamel, substance that covers the dentine, is naturally yellow (well, it can greyish/blueish white, but that’s a whole other story). Which means that hadn’t the Lumière invented cinema we’d be happy enough with a pallid golden grill.

Secondly — and here is a lesson for life rather than just in relation to dental hygiene — there’s no such a thing as free lunch, folks. Or did you really think that it would be this easy to get a milky grin? People literally gargle with bleach to get rid of their stains; merely using toothpaste to get whiter teeth is the equivalent of walking home from work to lose weight: alone it doesn’t work, but we pretend to believe it does every time we look at the mirror.